The Pallikaranai Marshland is a vital wetland ecosystem for Chennai and has long served as a natural buffer against floods, a reservoir for rainwater, and a haven for biodiversity. However, recent developments have raised alarms about its rapid degradation due to encroachments and pollution, underscoring the urgent need for its restoration. A study by the Uvakai Research Foundation titled Hydrological Insights from Pallikaranai catchment in Kovalam Basin – Volume I has revealed that 165 water bodies – including 31 lakes and 134 tanks – have disappeared from the Pallikaranai catchment area due to encroachments. The numbers translate to a loss of 7.35 sq km of water across areas such as Velachery, Injambakkam, Sembakkam, Nanganallur and Hasthinapuram. The study also highlighted that many of the remaining water bodies have retained water for fewer than 30 months over the past decade.
The Pallikaranai marshland is a Ramsar site, a wetland of international importance. It supports over 100 species of birds, including several migratory and endangered species such as the glossy ibis, purple swamphen, and the greater flamingo. It also harbors a range of aquatic plants, reptiles, and amphibians, making it one of the most biologically diverse ecosystems in South India. The presence of such biodiversity in an urban area like Chennai is not only rare but also invaluable for ecological research, education, and urban ecological balance.
In the context of climate change, wetlands act as carbon sinks and help regulate urban temperatures. During extreme weather events such as the increasingly frequent cyclones and heavy monsoons affecting Chennai, wetlands like Pallikaranai can absorb the excess rainwater and help prevent or mitigate flooding.
According to DT Next, the Pallikaranai catchment area includes a network of water bodies that collectively store up to 37.5 million cubic meters of water; the extent of loss reported by the study, therefore, raises grave concerns about the increased risk of urban flooding. The marshland’s capacity to absorb rainwater has diminished, already evident by the increased instances of urban flooding, particularly in low-lying areas like Velachery. Moreover, the marshland’s role in groundwater recharge is critical for the city’s water security. Its degradation threatens the sustainability of water resources, especially during periods of drought.
Various government bodies, including the Tamil Nadu Forest Department, have taken steps to demarcate and protect portions of the marshland. A part of it has been declared a reserve forest, which offers some legal protection. However, enforcement remains a significant challenge.
Awareness campaigns spearheaded by local communities as well as environmental activists have played a crucial role in drawing attention to the marshland’s plight, prompting interventions from the National Green Tribunal (NGT). Despite these measures, illegal dumping, construction, and road building have continued, highlighting a gap between policy and implementation. In fact, the adjacent Perungudi dumpyard is a significant source of pollution. In April 2025, The Hindu published a report about untreated leachate – contaminated liquid from decomposing waste – being discharged directly into the marshland. The article quoted an expert from Anna University – the Project Management Consultant for the GCC regarding the Perungudi dumpyard – who raised concerns that the untreated waste may have affected the colour and odour of groundwater. GCC has reportedly resumed biomining activities after resolving contractual disputes, aiming to process the remaining eight lakh tonnes of waste by August 2025. However, the continued dumping of approximately 3,000 tonnes of waste daily into the area remains a problem.
The restoration of Pallikaranai is not merely an environmental issue; it is a key contributor to the city’s climate resilience. Experts argue for a unified wetland authority to oversee its management, along with stricter penalties for violators. This is a sensible approach considering that restoration measures must necessarily tackle a variety of problems. Apart from implementing the necessary means to prevent further encroachments, the Pallikaranai marshland is in requirement of desilting projects that enhance its capacity to store rainwater; it must also be protected from untreated waste and leachate. Community engagement is key, especially considering the amount of active public interest in restoring the marshland – much can be done to involve local communities and activists and offer opportunities for participatory governance. It would also do well for the proposed unified authority to establish dedicated resources to conduct ongoing research that helps monitor and study the marshland’s health – the insights stand to be crucial in informing policy decisions going forward.